Much attention has been given to the preservation of our water supplies and resources, particularly since the mid 1960's. Agencies have become aware of the health effects of toxic pollutants on humans and the increased demands for potable water in this country and the world. Government agencies, for example, the Environmental Protection Agency (EPA), have responded by establishing maximum contaminant levels for many toxic chemical compounds. Today, once a chemical regulated under government law is identified in soil or water above the maximum contaminant level, facility operators or property owners are required to initiate assessment and remediation of the contamination. In some cases, the cost of cleaning up discharges of certain chemicals can greatly exceed the value of the contaminated property. In the past, the remediation of contaminated soil involved excavation and disposal of the impacted media. However, if the contaminant had reached the groundwater, the risk to the public welfare, remedial cost, and amount of time required to remove the contaminants increased substantially.
Biological treatment of water contaminants or organic chemicals with total petroleum hydrocarbons (TPH) and other contaminants has become an important process in controlling the pollution of the aquatic environment from industrial sources. The mineralization of organic chemicals depends on the nature of the chemical compounds involved. Some chemicals that find their way into the aquifer from industrial processes or natural processes resist degradation and are recalcitrant in nature; thereby accumulating in the environment.
It is well known that natural remediation occurs when facilitated by aerobic compounds in the soil. The injection of an oxygen release compound into the soil has been previously performed with a target of reducing the contaminants at a site. Some of these results are described in The ORC Oracle Newsletter 3:1, published by Regenesis.
This prior art method was a passive anaerobic biodegradation and was slow, incomplete and limited in its scope of impact. Since the system was passive, it was reliant on groundwater flow to distribute dissolved oxygen. Therefore, only groundwater downstream of the well was within the impacted area. Further, when the flow of groundwater was slow, the attenuation rate of the leached dissolved oxygen was correspondingly slow.